Listening to Shhhh in the City

To Tune Out Distractions, White Noise Climbs to the Top of Playlists

By

Aatekah Mir

August 31, 2011

Some of the hottest tracks on digital playlists: sounds of an oscillating fan, a waterfall and crickets.

White noise and other soothing sounds, once mainly played on machines to aid nighttime sleep, are increasingly helping make daytime hours more serene. When played through headphones, the sounds help people tune out chatty co-workers, pounding jackhammers and the dentist's drill.

A Rainbow of Sound

ENLARGE

White noise and other soothing sounds, once mainly played on machines to aid nighttime sleep, are increasingly helping make daytime hours more serene.
Getty Images

Sound is classified by its audible frequencies and associated with a color based on where it falls on the spectrum of high to low frequencies. White noise is unique in that it's random and includes all frequencies—akin to how white light has all the colors in the spectrum—and sounds like a hissing noise.

Janet Berkman, a 51-year-old retired project manager, in Toronto prefers the sounds of storms, wind, rain and running water when she is on the subway or trying to read in busy surroundings. Ms. Berkman started listening to the sounds late last year after she realized it helped her focus and concentrate. "Life is getting noisier," she says, and listening to these sounds "kind of empties out my brain."

To make the soothing sounds, developers take computer-generated sounds or sounds recorded in nature and make an audio file that usually is "looped," or repeated. These digital files are then available at the iTunes store and on other websites.

After HeavyDutyApps in December released an app called Sleep Pillow Ambiance to help people sleep, it quickly realized that many customers used it during the day as well. "The usage varies from people who need help concentrating while working in noisy environments, commuters who need a break from train noise and travelers that need a peaceful environment," says Benny Shaviv, chief executive of the Westchester, N.Y.-based company. The $1.99 app has had more than 1.6 million downloads, says Mr. Shaviv. "By January we were among the Top 50 apps in the Healthcare and Fitness category in iTunes."

White noise and other soothing sounds are increasingly helping make daytime hours more serene. WSJ's Emily Nelson explains more on Lunch Break.

Most popular are sounds from nature: rain, wind, waves crashing on the beach and crickets, Mr. Shaviv says. But the app also includes some unexpected sounds, such as cold drink with ice, brushing hair and horse running in field.

Frequent travelers also favor the sound of an airplane cabin—but not the noise of coach. "A lot of people who have to sit in the economy class want to listen to the business-class cabin sounds," Mr. Shaviv adds. (The business-class soundtrack doesn't have the sounds of babies crying or chattering people.)

SimplyNoise.com offers 99-cent apps called soundscapes that are downloaded about 400 times a day. Thunderstorm is the most popular downloaded noise.

Jared Kowalski, a 34-year-old stand-up comedian in Aliso Viejo, Calif., has created a customized mix using a TMSoft app called White Noise. "My favorite one reminds me of sitting in my aunt's house," he says. The track includes the sound of a grandfather clock ticking, a cat purring and a sprinkler spraying. Mr. Kowalski says he suffers from anxiety attacks and uses the sounds largely as a relaxation tool, such as when stuck in traffic or while he's waiting to perform.

He has also downloaded sounds of the Amazon rain forest from a Discovery Channel podcast, which he listens to on his iPod. "I plug my earphones in and get away from the world," he says.

What makes noise white? Sound is classified by its audible frequencies and associated with a color based on where it falls on the spectrum of high to low frequencies. White noise is unique in that it includes all frequencies—akin to how white light has all the colors in the spectrum—and sounds like a hissing noise.

One small study examined white noise in a classroom environment. The research, led by Goran Soderlund and Sverker Sikström of Stockholm University, looked at 51 students at a secondary school in Norway and found that those who normally had difficulty paying attention performed better when white noise was added to the classroom. The findings were published last year in the journal Behavioral and Brain Functions.

The authors theorized that white noise boosted neural activity, helping the brain work more efficiently. The study predicted that white noise could help children with attention deficit hyperactivity disorder (ADHD) learn to focus on schoolwork better.

Daytime white-noise listeners say the sounds serve two main purposes: to block out distractions and lessen sounds that cause anxiety, such as sirens.

"Certain types of noises can be relaxing," says Robert C. Fifer, director of audiology and speech language pathology at the University of Miami. White noise can be used to create a more relaxing working environment, masking sounds and promoting a sense of privacy, he says.

Developers of these apps say they frequently get requests for new sounds. Steven Jian, co-owner of Simply Noise, has received requests for the sound of passing cars and airport noises. Mr. Shaviv of HeavyDutyApps got a request for a sonar noise from a former sailor who served on a submarine.

Todd Moore, founder and CEO of TMSoft, the maker of an app called White Noise, says he created a hair-dryer sound at one woman's request. "She told me that she could not sleep without listening to it and that she had burned [out] six hair dryers over the years."

--Saabira Chaudhuri contributed to this article.

How White Noise Works

What people think of as "white noise" may actually be pink noise or brown noise or any number of other colors.

Sound is associated with a color based on where it falls on an audio spectrum of high to low frequencies. White noise contains random sounds across all frequencies and "sounds very much like a hiss because everything is changing in every sample," says Daniel Ellis, associate professor of electrical engineering at Columbia University in New York.

Pink noise, on the other hand, blends some high and lower frequencies, so it sounds like a hiss with a low rumble, he adds. Brown noise shifts to the lower end of the spectrum and sounds like rumbling.

The most effective noise at blocking out other sounds is white noise because it covers the largest range on the spectrum, says Andrew Catellier, an electronics engineer at the Boulder, Colo.-based National Telecommunications & Information Administration, which publishes a glossary of sounds' color classifications.

Distinguishing noises by their frequencies is a useful tool for scientists and engineers working on practical applications, such as building a cellphone system or an ultrasound machine.

Calling sounds like rain or thunder white noise is somewhat of a misnomer, but the makers of downloadable apps and sleep machines use the term anyway.

"The average person has no idea what kind of noise they are listening to," says Robert C. Fifer, director of audiology and speech language pathology at the University of Miami.

—Saabira Chaudhuri

Corrections & Amplifications Saabira Chaudhuri wrote 'How White Noise Works.' An earlier version of this article misspelled her surname Chaudhury.

This copy is for your personal, non-commercial use only. Distribution and use of this material are governed by our Subscriber Agreement and by copyright law. For non-personal use or to order multiple copies, please contact Dow Jones Reprints at 1-800-843-0008 or visit www.djreprints.com.